A card having a magnetic stripe is widely used in systems for identifying a particular individual (The recognition card is abbreviated as an M/S card). For example, in a card to be used for a deposit or withdrawing apparatus installed in a bank (hereinafter referred to as "deposit card") there are stored a code for recognizing the genuineness of the card and a password code for judging whether a card possessor is the registered user of the card or not. Accordingly, the deposit apparatus is designed to read out the genuineness code in the card to judge whether the card is genuine or not, to instruct the card possessor to input a password code from the keyboard, and to judge whether the card possessor is an authorized card possessor or not based upon the result of comparison of the input password code with the password code registered in the card. In this system, a numeral or symbol sequence which is relatively easy to memorize is appropriate for use as a password code.
The above described method is widely used because the status of the card possessor is relatively easily judged.
However, this system has a few disadvantages as described below:
The first disadvantage arises by the fact that the password code must be memorized by the card possessor. That is, the safety against unauthorized use is inevitably lowered because a card possessor is likely to use a simple password code so as to be able to memorize it easily. However, when a complicated code such as an account number is used instead of the password code, it is very troublesome or difficult to memorize the code, and furthermore there arises an anxiety of the code being stolen. As a consequence, there results no improvement in the safety against unauthorized use.